CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priorities to Chinese patent applications No.
201710042287.8 titled "ELECTRICAL CONNECTOR, FLUID STATE TEST DEVICE AND FLUID HEAT EXCHANGE SYSTEM",
filed with the Chinese State Intellectual Property Office on January 20, 2017, and
No.
201611270743.6 titled "ELECTRICAL CONNECTOR, FLUID STATE TEST DEVICE AND FLUID HEAT EXCHANGE SYSTEM",
filed with the Chinese State Intellectual Property Office on December 30, 2016, the
entire disclosures of which are incorporated herein by reference.
FIELD
[0002] This application relates to the technical field of electrical engineering, and particularly
to an electrical connector, a fluid state test device and a fluid heat exchange system.
BACKGROUND
[0003] An electric heating tube (or called a metal tubular electric heating element) is
a charged element configured to convert electrical energy into thermal energy. Compared
with conventional heating, the electric heating tube is pollution-free, convenient
to install and use, cheap, and belongs to environmentally friendly green production,
thus the electric heating tube is widely used. The electric heating tube may be applied
in multiple types of devices which require heat exchange process. For example, multiple
electric heating tubes may be combined into a heat exchange system to be installed
in a fluid channel of a saltpeter tank, a water tank, an oil tank, an acid-alkali
tank, a fusible metal melting furnace, an air heating furnace, a drying furnace, a
drying oven, a hot die and other devices.
[0004] In the case that multiple electric heating tubes are installed in an annular fluid
heat exchange transmission channel (a fluid channel) in a circular ring-shaped heating
device, the multiple electric heating tubes are respectively connected to fixed ends
of the electric heating tubes in the fluid channel to be fixed. Phases of the electrodes
of the multiple electric heating tubes are required to be connected in series or in
parallel to form a multiphase-load heat generation resource, and the multiple electric
heating tubes are supplied with power via alternating current. Therefore, the electrodes
of the electric heating tubes are required to be connected in a split-phase manner,
connected in series or connected in parallel by means of the electrical connector,
and further are connected with an external power supply. In this case, the electrical
connector itself, in addition to transmitting the electric energy, is located in the
channel where the fluid flows and becomes an obstacle in a flow path of the fluid-hot
air, which may cause forced vibration of the electrical connector and even induce
coupled vibration (i.e., resonance) of the electrical connector and the fluid, thereby
causing the electrical connector to be prone to be disengaged and separated from the
electrodes of the electric heating tube and thus causing a short-circuit fault.
[0005] In the conventional technology, in a method for addressing the above issue, the electrical
connector is prevented from vibrating, that is, the electrical connectors (such as
wires) connected to extraction electrodes of a number of branch electric heating tubes
are configured to pass through and be extracted from the fluid channel directly in
a radial direction of the fluid channel, and the extracted electrodes are connected
in series or connected in parallel outside the fluid channel, which may cause many
joints and make connection and fixing processes of external leads of a device complex.
Moreover, in the case that the fluid in the fluid channel is liquid, a strict sealing
process for preventing the fluid channel from leaking is further required. In another
method for addressing the above issue, in the case that the fluid in the fluid channel
is liquid, the electrical connector is not allowed to be extracted to the outside,
and in this case, multiple electrical connectors must be connected in series or in
parallel inside the fluid channel. In the case that insulation flexible leads are
selected as the electrical connector for connecting the electrodes of the electric
heating tubes, in order to prevent the leads from resonating in the fluid under the
action of fluid pressure, the insulation leads are required to be fixed to an inner
wall of the fluid channel, and after failure of insulation between insulation layers
of the leads and the metal inner wall of the fluid channel, discharge of the electrical
connector may be caused, resulting in a short-circuit fault of the entire heat exchange
system.
[0006] Therefore, there is an urgent demand for a new electrical connector, a fluid state
test device and a fluid heat exchange system.
SUMMARY
[0007] An object of the present application is to provide an electrical connector, a fluid
state test device and a fluid heat exchange system, which may measure and monitor
a flow speed of a fluid without affecting a fluid flow field where the electrical
connector, the fluid state test device and the fluid heat exchange system are located.
[0008] Another object of the present application is to provide an electrical connector,
a fluid state test device and a fluid heat exchange system, which may measure and
monitor a fluid pressure without affecting a fluid flow field where the electrical
connector, the fluid state test device and the fluid heat exchange system are located.
[0009] Another object of the present application is to provide an electrical connector,
a fluid state test device and a fluid heat exchange system, which may measure and
monitor a fluid resistance without affecting a fluid flow field where the electrical
connector, the fluid state test device and the fluid heat exchange system are located.
[0010] Another object of the present application is to provide an electrical connector,
a fluid state test device and a fluid heat exchange system, which may measure and
monitor the frequency of a lateral vibration of the electrical connector without affecting
a fluid flow field where the electrical connector, the fluid state test device and
the fluid heat exchange system are located.
[0011] Another object of the present application is to provide an electrical connector,
a fluid state test device and a fluid heat exchange system, which may suppress a longitudinal
vibration and/or lateral vibration of the electrical connector itself without affecting
a fluid flow field where the electrical connector, the fluid state test device and
the fluid heat exchange system are located.
[0012] According to one aspect of the present application, an electrical connector configured
to measure a state of fluid in a flow channel is provided. The electrical connector
includes a main body portion, connection portions, a total pressure acquisition portion
and a static pressure acquisition portion. The connection portions allow the main
body portion to be electrically connected to a charged element provided in the flow
channel. The total pressure acquisition portion includes a total pressure measuring
hole in a first part, facing a flow direction of the fluid, of the main body portion.
The static pressure acquisition portion includes a static pressure measuring hole
provided in a second part, parallel to the flow direction of the fluid, of the main
body portion.
[0013] According to another aspect of the present application, a fluid state test device
is provided, which includes an electrical connector and a first pressure measurement
portion. The electrical connector includes a main body portion, connection portions,
a total pressure acquisition portion and a static pressure acquisition portion. The
connection portion allows the main body portion to be electrically connected to a
charged element provided in a flow channel. The total pressure acquisition portion
includes a total pressure measuring hole provided in a first part, facing a flow direction
of fluid, of the main body portion. The static pressure acquisition portion includes
a static pressure measuring hole provided in a second part, parallel to the flow direction
of the fluid, of the main body portion. The first pressure measurement portion is
connected to the total pressure measuring hole and the static pressure measuring hole
respectively to measure a pressure state of the fluid.
[0014] According to another aspect of the present application, a fluid heat exchange system
is provided, and the fluid heat exchange system includes a flow channel through which
fluid flows, a charged element fixed to the flow channel, and the fluid state test
device described hereinabove. The charged element is an electric heating element,
and the electric heating element includes a heating body and an electrode located
at an end of the heating body. The electrical connector is connected to the electrode
of the electric heating element.
[0015] According to the present application, the structure of the electrical connector which
connects the electrodes of the electric heat source in a split-phase manner, in series
or in parallel is developed and the function is also extended, breaking through the
function in the conventional sense that a conductor can only perform the task of transmitting
electric energy, and allowing the electric connector further to have sensing, testing
and other functions, which makes a major breakthrough in the conventional technology.
According to the present application, the original flow field in a fluid system where
the electrical connector of the electrode of the electric heat source is located may
not be changed, and the sensor and the test system are not introduced around the electrical
connector of the electrode of the electric heat source, which avoids the destruction
to the flow field around the electrical connector of the electrode of the electric
heat source. And at least one of the following information may be obtained through
the present application: (1) information about forced vibration of the electrical
connector of the electrode of the electric heat source; (2) information about the
velocity of the fluid in the flow field where the electrical connector of the electrode
of the electric heat source is located; (3) information about the condition of convective
heat exchange between the electrical connector of the electrode of the electric heat
source and the fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016]
Figure 1 is a front view of an electrical connector in a state of being installed
in a fluid channel according to the present application.
Figure 2 is a partially schematic view of an electrical connector according to an
embodiment of the present application.
Figure 3 is a partially schematic view of an electrical connector according to another
embodiment of the present application.
Figure 4 is a schematic view showing the relationship between a ratio of width to
thickness and a resistance coefficient of an electrical connector according to the
present application.
Figure 5 is a top view of an electrical connector according to an embodiment of the
present application.
Figure 6 is a top view of an electrical connector according to another embodiment
of the present application.
Figure 7 is a partially schematic view of an electrical connector according to another
embodiment of the present application.
Figure 8 is a schematic cross-sectional view of an electrical connector according
to another embodiment of the present application.
Figure 9 is a partially schematic view of an electrical connector wound with a helical
wire according to the present application.
Figure 10 is a front view of an electrical connector in a state of being installed
in the fluid channel according to another embodiment of the present application.
Figure 11 is a schematic view of a fluid state test device according to an embodiment
of the present application.
Figure 12 is a schematic view of a fluid state test device according to another embodiment
of the present application.
Figure 13 is a schematic view of a fluid state test device according to another embodiment
of the present application.
Figure 14 is a schematic view of a circuit for a frequency calculation unit in the
fluid state test device shown in Figure 13.
Figure 15 is a schematic cross-sectional view of a fluid heat exchange system installed
with the electrical connector according to the present application.
Figure 16 is a schematic view showing the structure of an electric heating tube installed
in the fluid heat exchange system shown in Figure 15.
Figure 17 is a schematic plane outspread view showing a disposition relationship between
the electric heating tube in the fluid heat exchange system and the electrical connector
according to the present application.
Figure 18 is a schematic plane outspread view showing another disposition relationship
between the electric heating tube in the fluid heat exchange system and the electrical
connector according to the present application.
Reference Numerals:
100. |
electrical connector, |
110. |
main body portion, |
111. |
upstream side, |
112. |
first side, |
113. |
second side, |
|
|
114. |
first temperature sensing element mounting recess, |
115. |
second temperature sensing element mounting recess, |
116. |
downstream side, |
120. |
first connection portion, |
121. |
connection hole, |
122. |
connection surface, |
123. |
connection surface, |
130. |
second connection portion, |
140. |
total pressure acquisition portion, |
141. |
total pressure measuring hole, |
142. |
total pressure transmission channel, |
143. |
total pressure output port, |
150. |
static pressure acquisition portion, |
151. |
static pressure measuring hole, |
152. |
static pressure transmission channel, |
153. |
static pressure output port, |
160. |
twist portion, |
170. |
twist portion, |
180. |
first pressure measurement portion, |
181. |
first temperature sensing element, |
182. |
second temperature sensing element, |
190. |
frequency calculation unit, |
191. |
first bridge resistor, |
192. |
second bridge resistor, |
193. |
constant current source, |
194. |
power supply, |
195. |
amplifier, |
196. |
filter, |
197. |
flip-flop, |
198. |
converter, |
200. |
electric heating tube, |
201. |
metal outer tube, |
202. |
resistance wire, |
203. |
filler, |
204. |
electrode, |
205. |
insulation ceramic head, |
206. |
helical fin, |
210. |
back pressure acquisition portion, |
211. |
back pressure measuring hole, |
212. |
back pressure transmission channel, |
213. |
back pressure output port, |
220. |
helical wire, |
230. |
second pressure measurement portion, |
240. |
resistance coefficient calculation unit, |
241. |
multiplier, |
242. |
multiplier, |
243. |
divider, |
300. |
fluid channel, |
301. |
fixed end, |
400. |
electrical connector, |
410. |
main body portion, |
420. |
first connection portion, |
430. |
second connection portion. |
|
|
DETAILED DESCRIPTION OF EMBODIMENTS
[0017] Hereinafter, embodiments of the present application are described with reference
to the drawings. The following detailed description of the drawings is used to illustrate
principles of the present application by way of example, and the present application
is not limited to preferred embodiments described. The scope of the present application
is defined by the claims.
[0018] Figures 1 to 10 show an electrical connector 100 according to the present application.
The electrical connector 100 is configured to connect charged elements provided in
a fluid channel to electrically connect the charged element and a power supply or
electrically connect the charged elements with each other. The charged element may
be an electric heating element capable of generating heat, or may be another type
of charged element capable of achieving electricity conducting function. In an embodiment
shown in Figure 1, fluid flows inward in a direction perpendicular to the paper, and
a flow direction of the fluid is indicated by a circle within which an arrow tail
is located. Hereinafter, the structure of the electrical connector 100 is described
by taking the flow direction of the fluid as a reference.
[0019] Figure 1 is a front view of the electrical connector 100 in a state of being installed
in the fluid channel. The electrical connector 100 includes a main body portion 110,
and a first connection portion 120 and a second connection portion 130 which are respectively
located at two ends in a length direction of the main body portion 100. The main body
portion 110 includes an upstream side 111, a first side 112, a second side 113 and
a downstream side 116 (see Figure 2). The upstream side 111 is a surface, facing the
flow direction of the fluid, of the main body portion 110, and the upstream side 111
is impacted directly by the fluid in the fluid channel and generates a resistance
which impedes the fluid flow. The downstream side 116 is a surface away from the flow
direction of the fluid of the main body portion 110, and the downstream side 116 is
opposite to the upstream side 110 and is not impacted by the fluid in the fluid channel.
The first side 112 and the second side 113 are usually parallel to the flow direction
of the fluid. The first connection portion 120 and the second connection portion 130
are respectively located at two ends of the main body portion 110. The first connection
portion 120 has a connection hole 121, and a connection surface 122 and a connection
surface 123 facing to each other. The second connection portion 130 has a connection
hole 131, and a connection surface 132 and a connection surface 133 facing to each
other. The connection holes 121,131 may allow electrodes of two charged elements (see
Figure 16) to pass through. A portion, passing through the connection hole, of the
electrode is provided with threads, and the electrodes may be fixed to the respective
first connection portion 120 and the respective second connection portion 130 by a
fastener such as a nut, thus an electrical connection between two charged elements
respectively connected at two ends of the electrical connector 100 is achieved. Preferably,
the connection surfaces 122,123 and/or the connection surfaces 132,133 are flat surfaces,
thus facilitating pressing and fixing the electrode of the charged element after passing
through the connection holes by the fastener.
[0020] For the first side 112 and the second side 113, in order to allow a flow state of
the fluid passing through the first side 112 and a flow state of the fluid passing
through the second side 113 to be in substantially the same condition, preferably,
the first side 112 is parallel to the second side 113. In the embodiment shown in
Figure 1, the main body portion 110 is arc-shaped, that is, both the first side 112
and the second side 113 are curved surfaces. In other embodiments, as shown in Figure
2 and Figure 3, both first side 112 and the second side 113 are flat surfaces.
[0021] For the upstream side 111, in order to accurately acquire and measure a fluid pressure
applied on the upstream side 111, in an embodiment shown in Figure 2, the upstream
side 111 is a flat surface. Preferably, the upstream side 111 is a surface perpendicular
to the flow direction of the fluid. In another embodiment shown in Figure 3, the upstream
side 111 is a curved surface for reducing the resistance to the fluid. Furthermore,
a region, where a total pressure measuring hole 141 is provided, of the upstream side
111 is a flat surface.
[0022] In order to reduce the resistance of the upstream side 111 to the fluid and also
reduce the pressure applied by the fluid on the upstream side 111 in the flow direction
of the fluid, a size of the upstream side 111 in a direction perpendicular to the
flow direction of the fluid, that is a size of the upstream side 111 in a thickness
direction, should be reduced as much as possible. In the embodiment shown in Figure
1, the size of the upstream side 111 in the thickness direction is less than a size
of the main body portion 110 in a direction parallel to the flow direction of the
fluid, that is, a size of the main body portion 110 in a width direction. That is,
the size of the upstream side 111 in the thickness direction is less than a size of
the side (that is, the first side 112 and the second side 113) of the main body portion
110 in the width direction. In this way, the upstream side 112 has a small upwind
area and thus a low resistance is generated, and the upstream side 111 is not apt
to bend, and accordingly a low longitudinal vibration (vibration in the flow direction
of the fluid) is generated.
[0023] Further, for the electrical connector 100, with a rectangular cross-section of the
upstream side 111, that is, a projection section of the upstream side 111 on a plane
perpendicular to the flow direction of the fluid being rectangular, the resistance
of the electrical connector 100 to the fluid in the fluid channel may be reduced by
optimizing a characteristic dimension of the electrical connector 100 with a rectangular
cross-section, thus the longitudinal vibration of the electrical connector 100 may
be reduced. As shown in Figure 2, a width D of the electrical connector 100 is a size
of the electrical connector 100 in the direction parallel to the flow direction of
the fluid, and a thickness B is a size of the electrical connector 100 in the direction
perpendicular to the flow direction of the fluid. Therefore, a ratio of width to thickness
of the electrical connector 100 is defined as D/B. The pressure of the upstream side
111 of the electrical connector 100 is p
w and the pressure of the downstream side 116 of the electrical connector 100 is p
l, and thus the resistance of the upstream side 111 of the electrical connector 100
to the fluid is F=(p
w-p
l)A.
[0024] In the above equation, A indicates a projection area of the upstream side 111 of
the electrical connector 100, that is, an area, directly facing the flow direction
of the fluid, of the upstream side 111 of the electrical connector 100.
[0025] Both sides of the above resistance equation are divided by 0.5 ρ
aU
2A, and it may be obtained that C
d=C
p,w-C
p,l,
where ρ
a indicates the density of the fluid in the fluid channel, U indicates a speed of the
fluid in the fluid channel, C
p,w indicates a pressure coefficient of the upstream side 111, C
p,l indicates a pressure coefficient of the downstream side 116, and C
d indicates a coefficient of pressure generated by the electrical connector 100 to
the fluid that is, a resistance coefficient,.
[0026] In fact, the pressure p
w and the pressure coefficient C
p,w of the upstream side 100 may vary with the position of a flat surface or a curved
surface of the upstream side 100, while a downstream side pressure (or called a base
pressure) is almost constant for the reason that a region where the downstream side
is located is completely in a wake zone where the speed of the air flow is relatively
low. Figure 4 shows a curve illustrating a relationship between the resistance coefficient
Cd and the ratio of width to thickness D/B. It may be seen from the curve that, in
the case that the ratio of width to thickness D/B is about 0.5, ie., the width D is
half the thickness B, the resistance coefficient Cd is maximum, that is, the resistance
of the electrical connector 100 to the fluid in the fluid channel is maximum and a
longitudinal impact force acting on the electrical connector 100 is maximum, thereby
the induced longitudinal vibration of the electrical connector 100 is strongest. And
it may be seen from the curve that in the case that the ratio of width to thickness
D/B is greater than 0.5, the resistance coefficient Cd gradually decreases, and in
the case that the ratio of width to thickness D/B is greater than 4, the resistance
coefficient Cd tends to be constant, and as the ratio of width to thickness D/B increases,
the resistance coefficient Cd reaches a minimum, that is, the resistance of the electrical
connector 100 to the fluid in the fluid channel is minimum and the longitudinal impact
force acting on the electrical connector 100 is minimum, thereby the induced longitudinal
vibration of the electrical connector 100 is weakest.
[0027] In the fluid channel, the charged element is usually arranged in a direction parallel
to the flow direction of the fluid, and an electrode extending from an end of the
charged element is also usually parallel to the flow direction of the fluid. In order
to provide a connection hole in each of the first connection portion 120 and the second
connection portion 130 and to improve the stability of connection between the electrode
and the electrical connector 100, it is required to increase the areas of the connection
surfaces 122, 123 of the first connection portion 120 and the areas of the connection
surfaces 132, 133 of the second connection portion 130. In this embodiment, sizes
in the direction perpendicular to the flow direction of the fluid, of the connection
surfaces 122, 123 of the first connection portion 120 and of the connection surfaces
132, 133 of the second connection portion 130 are all greater than a size of the main
body portion 110 in the direction perpendicular to the flow direction of the fluid
(that is, a size of the upstream side 111). In the embodiment shown in Figure 1 or
Figure 5, the electrical connector 100 is formed by a substantially rectangular plate-like
component, and the plate-like component is made of a metallic material such as copper
or aluminum having a good electrical conductivity. In order to ensure a larger contact
surface between each of the first connection portion 120, the second connection portion
130 of the electrical connector 100 and an electrode 204 to facilitate mounting, a
twist portion 160 and a twist portion 170 each having a twist angle of 90 degrees,
are provided between the main body portion 110 and the first connection portion 120
and between the main body portion 110 and the second connection portion 130, respectively.
According to mounting conditions such as positions and orientations of the electrodes
of the charged element to be connected, the twist portions 160,170 may also have other
twist angles. Further, in other embodiments, the first connection portion 120 and
the second connection portion 130 may also be formed by other methods such as a molding
process. Figure 6 is a top view of the electrical connector 100 according to another
embodiment of the present application. As shown in the figure, alternatively, the
twist portions 160,170 may not be provided between the first connection portion 120
and the main body portion 110 and/or the second connection portion 130 and the main
body portion 110, that is, the twist angle is zero. Further, the first connection
portion 120 and the second connection portion 130 may be integrally formed with the
main body portion 110, or the first connection portion 120 and the second connection
portion 130 may be separately formed with respect to the main body portion 110.
[0028] In addition to transmitting electric energy, the electrical connector 100 may also
be configured to acquire and measure state parameters, such as pressure, temperature,
velocity and quantity of flow, of the fluid which flows through the electrical connector
100 in the fluid channel. As shown in Figures 5 to 7, the electrical connector 100
is configured to acquire pressures, including a total pressure, a static pressure,
a dynamic pressure and a back pressure, at some point in the fluid by a total pressure
acquisition portion 140, a static pressure acquisition portion 150 and a back pressure
acquisition portion 210 respectively, and the total pressure acquisition portion 140,
parameters, such as flow speed, flow rate and resistance coefficient, of the fluid
are calculated based on the above pressures. In the conventional technology, a pressure
detector or a sampling device is independently provided in the fluid channel to acquire
a pressure indication value at a signal source, and such interventional detection
may affect a measurement value to a certain extent and cannot reveal the condition
of an original state of a fluid field in the fluid channel. The electrical connector
100 according to the embodiment of the present application has both an acquisition
function and a measurement function, and an independent detector does not be introduced
to the fluid channel, so that the state parameters of the fluid can be measured more
accurately.
[0029] Figure 5 and Figure 6 show the total pressure acquisition portion 140 provided on
the electrical connector 100. The total pressure acquisition portion 140 includes
a total pressure measuring hole 141 provided in the upstream side 111, a total pressure
output port 143 provided in the first connection portion 120, and a total pressure
transmission channel 142 provided in the main body portion 110 to allow the total
pressure measuring hole 141 to be in communication with the total pressure output
port 143. The total pressure measuring hole 141 is provided in the upstream side 111,
and the upstream side 111 faces the direction of the upwind inflow in the fluid channel,
and the total pressure measuring hole 141 has an opening directly facing the direction
of the inflow for measuring a total pressure (or a stagnation pressure) generated
by the fluid on the upstream side 111. The total pressure measuring hole 141 is a
smooth hole without sharp edges, and may have a circular shape, an oval shape, a polygonal
shape and the like. When the fluid is in a motion state, the upstream side 111 facing
the flow direction of the fluid is not only subjected to a static pressure from the
fluid, but also subjected to a dynamic pressure from the fluid, and the static pressure
and the dynamic pressure together form a total pressure acting on the upstream side
111. Since the dynamic pressure has directivity, that is, the dynamic pressure takes
effect in the flow direction of the fluid, preferably an axial direction of the total
pressure measuring hole 141 is arranged in the flow direction of the fluid, so that
the total pressure measuring hole 141 is collinear with the flow direction of the
fluid and an included angle between the axial direction of the total pressure measuring
hole 141 and the flow direction of the fluid is zero. The total pressure measuring
hole 141 may be arranged at any positions on the upstream side 111. Preferably, the
total pressure measuring hole 141 is arranged at a substantially central position
of the upstream side 111, for measuring a maximum flow speed of the fluid which is
going to flow into the total pressure measuring hole 141, that is, the fluid located
upstream of the position of the total pressure measuring hole 141. The total pressure
transmission channel 142 is provided in the main body portion 110, and the total pressure
transmission channel 142 has an entrance in communication with the total pressure
measuring hole 141 and an exit extending to the first connection portion 120 of the
electrical connector 100, for transmitting the total pressure to the total pressure
output port 143. The total pressure transmission channel 142 may be directly formed
in the main body portion 110. Or, the total pressure transmission channel 142 is an
independent pipeline, and is embedded in a preformed slot in the electrical connector
100 in such a manner that a top surface of the total pressure transmission channel
142 does not go beyond a surface of the upstream side 111, and preferably, the top
surface of the total pressure transmission channel 142 is flush with the surface of
the upstream side 111. Furthermore, the top surface of the total pressure transmission
channel 142 has the same surface structure as the surface of the upstream side 111,
for example, an anti-corrosive layer is coated on the entire upstream side including
the top surface of the total pressure transmission channel 142. Alternatively, the
total pressure transmission channel 142 is an independent pipeline passing through
a preformed channel provided in the electrical connector 100. The total pressure output
port 143 may be provided in a surface of the main body portion 110 or a surface of
each of the connection portions 120, 130. In order to avoid affecting the flow field,
the total pressure output port 143 is provided in the first connection portion 120
or the second connection portion 130 and is in communication with the exit of the
total pressure transmission channel 142. As shown in Figure 5, the total pressure
output port 143 is provided in an end surface of the first connection portion 120.
Alternatively, the total pressure output port 143 may also be provided in an end surface
of the second connection portion 130. Alternatively, the total pressure output port
143 may be provided in the connection surface 122 or the connection surface 123 of
the first connection portion 120 or in the connection surface 132 or the connection
surface 133 of the second connection portion 130. As shown in Figure 6, the total
pressure output port 143 may be provided in the connection surface 122 of the first
connection portion 120.
[0030] Figure 5 and Figure 6 show the static pressure acquisition portion 150 provided on
the electrical connector 100. The static pressure acquisition portion 150 includes
a static pressure measuring hole 151 provided in the first side 112, a static pressure
output port 153 provided in the first connection portion 120, and a static pressure
transmission channel 152 provided in the main body portion 110 to allow the static
pressure measuring hole 151 to be in communication with the static pressure output
port 153. The static pressure measuring hole 151 is provided in the first side 112
and is arranged in such a manner that no dynamic pressure component is generated by
the fluid in the static pressure measuring hole 151. Preferably, an axial direction
of the static pressure measuring hole 151 is perpendicular to the flow direction of
the fluid. Alternatively, the static pressure measuring hole 151 may also be provided
in the second side 113. The number of the static pressure measuring holes 151 may
be more than one. In the case that multiple static pressure measuring holes 151 are
provided, the static pressure measuring holes 151 may be provided in one or both of
the first side 112 and the second side 113. Further, the static pressure measuring
holes 151 may be provided at any positions on the first side 112 and/or the second
side 113. Preferably, the static pressure measuring hole 151 is provided at a position
close to the total pressure measuring hole 141 in the flow direction of the fluid,
for example, the static pressure measuring hole 151 is provided on a straight line
in the flow direction of the fluid. Preferably, the axial direction of the static
pressure measuring hole 151 perpendicularly intersects the axial direction of the
total pressure measuring hole 141. The static pressure transmission channel 152 is
provided in the main body portion 110, and the static pressure transmission channel
152 has an entrance in communication with the static pressure transmission channel
152 and an exit extending to the first connection portion 120 of the electrical connector
100, for transmitting the static pressure to the static pressure output port 153.
The static pressure transmission channel 152 may be directly provided in the main
body portion 110. Alternatively, by taking the static pressure transmission channel
152 provided in the first side 112 as an example, the static pressure transmission
channel 152 is an independent pipeline, and is embedded in a preformed slot in the
electrical connector 100 in such a manner that a top surface of the static pressure
transmission channel 152 does not go beyond a surface of the first side 112, and preferably,
the top surface of static pressure transmission channel 152 is flush with the surface
of the first side 112. Furthermore, the top surface of the static pressure transmission
channel 152 has the same surface structure as the surface of the first side 112, for
example, an anti-corrosive layer is coated on the entire first side including the
top surface of the static pressure transmission channel 152. Alternatively, the static
pressure transmission channel 152 is an independent pipeline passing through a preformed
channel provided in the electrical connector 100. The static pressure output port
153 is provided in the first connection portion 120 or the second connection portion
130 and is in communication with the exit of the static pressure transmission channel
152. As shown in Figure 5, the static pressure output port 153 is provided in the
end surface of the first connection portion 120. Alternatively, the static pressure
output port 153 may also be provided in the end surface of the second connection portion
130. Alternatively, the static pressure output port 153 may be provided in the connection
surface 122 or the connection surface 123 of the first connection portion 120 or in
the connection surface 132 or the connection surface 133 of the second connection
portion 130. As shown in Figure 6, the static pressure output port 153 is provided
in the connection surface 123 of the first connection portion 120. Further, the static
pressure output port 153 and the total pressure output port 143 may be provided in
the same connection portion or different connection portions. In the case that the
static pressure output port 153 and the total pressure output port 143 extend out
from the same connection portion, the static pressure output port 153 and the total
pressure output port 143 may be provided in the same end and/or connection surface
or in different ends and/or connection surfaces. For example, the static pressure
output port 153 may be provided in the connection surface 123 and the total pressure
output port 143 may be provided in the connection surface 122, or the static pressure
output port 153 may be provided in the connection surface 122 and the total pressure
output port 143 may be provided in the connection surface 123.
[0031] The pressure applied by the fluid on the upstream side 111 is acquired and measured
in the present application based on the principle of a pitot-static tube. The total
pressure measuring hole 141 and the total pressure transmission channel 142 are in
communication with each other to form a pitot tube, and the static pressure measuring
hole 151 and the static pressure transmission channel 152 are in communication with
each other to form a static tube. By the total pressure output port 143 and the static
pressure output port 153, the dynamic pressure, that is, a difference between the
total pressure and the static pressure, of the fluid acting at the total pressure
measuring hole 141 may be obtained. By substituting the dynamic pressure of the fluid
into a Bernoulli equation, the flow speed of the fluid at the total pressure measuring
hole 141 may be derived, and further the flow rate may be calculated.
[0032] Figure 7 shows the back pressure acquisition portion 210 provided on the electrical
connector 100. As described hereinbefore, in order to calculate the resistance coefficient
C
d, the back pressure acquisition portion 210 may be further provided to acquire and
measure a downstream side pressure p
l of the electrical connector 100. The back pressure acquisition portion 210 includes
a back pressure measuring hole 211 provided in the downstream side 116, a back pressure
output port 213 provided in the connection portion (not indicated) and a back pressure
transmission channel 212 provided in the main body portion (not indicated) to allow
the back pressure measuring hole 211 to be in communication with the back pressure
output port 213. The back pressure measuring hole 211 is provided in the downstream
side 116, and the downstream side 116 is away from the direction of the upwind inflow
in the flow channel, and the back pressure measuring hole 211 has an opening opposite
to the direction of the inflow and is configured to acquire and measure the back pressure
(or the base pressure) generated by the fluid on the downstream side 116. The back
pressure measuring hole 211 is a smooth hole without burrs, and the shape of the hole
may be a circle, an ellipse, a polygon or the like. The back pressure measuring hole
211 may be arranged at any positions on the downstream side 116. The back pressure
transmission channel 212 is provided in the main body portion 110, and the back pressure
transmission channel 212 has an entrance in communication with the back pressure measuring
hole 211 and an exit extending to the connection portion of the electrical connector
100, for transmitting the back pressure to the back pressure output port 213. The
back pressure transmission channel 212 may be directly formed in the main body portion.
Alternatively, the back pressure transmission channel 142 is an independent pipeline
and embedded in a slot preformed in the electrical connector 100 in such a manner
that a top surface of the back pressure transmission channel 212 does not go beyond
a surface of the downstream side 116, and preferably, the top surface of the back
pressure transmission channel 212 is flush with the surface of the downstream side
116. Furthermore, the top surface of the back pressure transmission channel 212 has
the same surface structure as the surface of the downstream side 116, for example,
a coating such as an anti-corrosive layer is coated on the entire downstream side
116 including the top surface of the back pressure transmission channel 212. Alternatively,
the back pressure transmission channel 212 is an independent pipeline passing through
a preformed channel provided in the electrical connector 100. The back pressure output
port 213 may be provided in the surface of the main body portion 110 or in the surface
of each of the first connection portion 120 and the second connection portion 130.
In order to avoid affecting the flow field, preferably the back pressure output port
213 is provided in the first connection portion 120 or the second connection portion
130 and is in communication with the exit of the back pressure transmission channel
212. Similarly to the total pressure output port 143 and the static pressure output
port 153, the back pressure output port 213 may be provided in the end surface of
the first connection portion 120 or the second connection portion 130. Alternatively,
the back pressure output port 213 may further be provided in the connection surfaces
122, 123 of the first connection portion 120 or in the connection surfaces 132,133
of the second connection portion 130.
[0033] According to the present application, the electrical connector 100 itself is electricity
conductive. In the case that the charged element connected to the electrical connector
100 is energized with alternating current, a current density in a cross-section of
the electrical connector 100 is not uniform, and a skin effect may occur and the current
is mainly concentrated on a surface of the electrical connector 100, the current density
on a central region of the cross-section of the electrical connector 100 is small
and is practically small even when a high-frequency current is transmitted, thus the
electrical connector 100 has no application value. Therefore, by providing the total
pressure acquisition portion 140, the static pressure acquisition portion 150 and
the back pressure acquisition portion 210 in the electrical connector 100, materials
for manufacturing the electrical connector 100 are saved and a path for measuring
and sampling the pressure (or the flow speed) is formed, the function of conducting
electricity of the electrical connector 100 may not be affected and the electrical
connector 100 may achieve a function of acquiring and measuring a flow state of the
fluid.
[0034] Further, when the electrical connector 100 transmits electric energy in the fluid,
in addition to the longitudinal vibration caused by the action of the fluid pressure
described above, a coupled vibration of the electrical connector 100 with the fluid
may be further caused, causing a Karman vortex street destruction phenomenon. According
to the Karman vortex street principle, as shown in Figure 1, when the electrical connector
100 is located in the fluid, the Karman vortex street phenomenon may be generated
on the first side 112 and the second side 113 by the fluid flowing through the first
side 112 and the second side 113 respectively, which causes that regular downstream
shedding of a vortex occurs on the two sides, and the fluid located at a side where
the shedding of the vortex occurs has an energy loss due to the backflow phenomenon,
thus having a flow speed slower than the flow speed of the fluid at another side where
no shedding of the vortex occurs. According to the Newton's cooling law formula for
quantitatively calculating a convective heat exchange speed in heat transfer theory,
the convective heat exchange speed is directly proportional to the 0.8th power of
the flow speed of the fluid. Therefore, in the case the shedding of the vortex occurs
alternately on the two sides of the electrical connector 100, a temperature of a side
wall where the shedding of the vortex occurs is inconsistent with a temperature of
a side wall where no shedding of the vortex occurs. Such temperature change frequency
corresponds to the frequency of an alternating force applied by the fluid on the two
sides and a lateral vibration frequency of the electrical connector 100 in the direction
perpendicular to the flow direction of the fluid and caused by the alternating force,
thus measurement of the lateral vibration frequency of the electrical connector may
be achieved by measuring the temperature change frequency. In the conventional technology,
a pressure detector or a pressure sampler is independently provided in the flow channel
to acquire a reliable pressure indication value at a signal source. Such interventional
detection may affect the measuring value to a certain extent, and cannot reveal the
condition of the original state of a fluid field in the flow channel. In the present
application, the lateral vibration frequency of the electrical connector 100 is measured
according to the Karman vortex street principle. Through the temperature sensing elements
respectively provided on the first side 112 and the second side 113, the temperature
change caused by the Karman vortex street phenomenon on the two sides is obtained,
and based on the temperature change described above, the frequency of the alternating
force acting on the two sides and the lateral vibration frequency of the electrical
connector 100 are calculated. The electrical connector 100 according to the embodiment
of the present application itself has the function of acquiring and measuring temperature
parameters, and does not have to arrange an independent detector in the flow channel,
thus, the electrical connector 100 may be configured to measure the state parameter
of the fluid more accurately.
[0035] Figure 5 and Figure 6 show a first temperature sensing element 181 and a second temperature
sensing element 182 of the electrical connector 100. The first temperature sensing
element 181 and the second temperature sensing element 182 are respectively arranged
on the first side 112 and the second side 113, for acquiring temperatures of the fluid
flowing through the first side 112 and the second side 113 respectively. Figure 8
is a schematic cross-sectional view of the electrical connector 100, and Figure 8
further shows the arrangement of the first temperature sensing element 181 and the
second temperature sensing element 182. In Figure 8, the first temperature sensing
element 181 and the second temperature sensing element 182 are respectively provided
at opposite positions on the first side 112 and the second side 113 in an electrically
insulated manner, for example, provided at a central position of the first side 112
and a central position of the second side 113. Alternatively, the first temperature
sensing element 181 and the second temperature sensing element 182 may be provided
at any positions of the first side 112 and the second side 113, and the number of
the first temperature sensing elements 181 and the number of the second temperature
sensing elements 182 may be more than one. Furthermore, the first temperature sensing
element 181 and the second temperature sensing element 182 should be maintained in
a positional relationship of being opposite to each other and have a one-to-one correspondence
in number. In order to prevent the first temperature sensing element 181 and the second
temperature sensing element 182 from impeding the fluid flowing through a sensing
surface of the first temperature sensing element 181 and the fluid flowing through
a sensing surface of the second temperature sensing element 182, an outer surface
of the first temperature sensing element 181 and an outer surface of the second temperature
sensing element 182 do not go beyond the surface of the first side 112 and the surface
of the second side 113. Preferably, the outer surface of the first temperature sensing
element 181 is flush with the surface of the first side 181, and the outer surface
of the second temperature sensing element 182 is flush with the surface of the second
side 113. Furthermore, the outer surface of the first temperature sensing element
181 and/or the outer surface of the second temperature sensing element 182 has the
same surface structure, for example the same roughness, as the surface of the first
side 1 12 where the first temperature sensing element 181 is located and/or the surface
of the second side 113 where the second temperature sensing element 182 is located.
In the process that the fluid flows through the sides, a condition of a fluid boundary
layer contacting with the first side 112 and the second side 113 does not change,
and thus an original flow field is not destroyed. In order to install the first temperature
sensing element 181 and the second temperature sensing element 182, a first temperature
sensing element mounting recess 114 and a second temperature sensing element mounting
recess 115 may be provided at opposite positions on the first side 112 and the second
side 113. In order to maintain the insulation between the temperature sensing elements
and the electrical connector 100, it is preferable that an electrically insulation
layer may be coated on each of a surface of the first temperature sensing element
mounting recess 114 and a surface of the second temperature sensing element mounting
recess 115.
[0036] According to the present application, in addition to transmitting electric energy,
the electrical connector 100 may be configured to measure the frequency of an alternating
force applied by the fluid flowing through the electrical connector 100 in the flow
channel on the electrical connector 100 in the direction perpendicular to the flow
direction of the fluid, without introducing an independent sensor and a test system
thereof and thus not changing the flow field where the electrical connector 100 is
located, and further a frequency parameter of the lateral vibration induced by the
alternating force of the electrical connector 100 is obtained.
[0037] Further, it may be known from an inducing mechanism of the lateral vibration of the
electrical connector 100 in the flow channel of the fluid that, the lateral vibration
is caused by a Karman vortex street effect generated by the fluid on the two sides
112,113 of the electrical connector 100. When the fluid flows through the electrical
connector 100, alternating shedding of the vortex may occur on the two sides 112,113
of the electrical connector 100 in an orderly manner. For the electrical connector
100, a helical protrusion may be provided on the surface of the electrical connector
100 to reduce the lateral vibration of the electrical connector 100. As shown in Figure
9, a helical wire 220 with a certain pitch is wound around the electrical connector
100, which may destroy the orderliness of the alternating shedding of the vortex occurring
on the two sides 112,113 of the electrical connector 100, so that the vortexes on
the two sides 112,113 of the electrical connector 100 may shed synchronously or shed
alternately in an irregular manner, thus the lateral vibration of the electrical connector
100 is suppressed. The pitch of the helical wire 220 may be adjusted according to
the lateral vibration frequency of the electrical connector 100. Preferably, the pitch
of the helical wire 220 is optimally designed based on a maximum lateral vibration
amplitude of the electrical connector 100. Further, the helical wire 220 may be made
of a metallic material, however, the helical wire 220 is not allowed to form a closed
circuit. Preferably, the helical wire 220 may be made of a non-conductive material,
for example, a non-metallic material. Alternatively, the helical protrusion may further
be integrally formed on the surface of the electrical connector 100. For example,
in the case that a coating such an anti-corrosive layer is coated on the surface of
the electrical connector 100, the helical protrusion is integrally formed on the surface
of the electrical connector 100 by an impregnation process. Preferably, the position
of the helical protrusion should be configured to avoid the region, where at least
one of the measuring holes 141,151,211 is located, on the surface of the electrical
connector 100, so as to avoid affecting the flow field around the measuring holes
to avoid causing a measurement error.
[0038] Figure 10 is a schematic view of an electrical connector 400 according to another
embodiment of the present application. The electrical connector 400 includes a main
body portion 400 and connection portions 420,430. The main body portion 400 is annular.
Each of the connection portions 420,430 has an end connected to the annular main body
portion 400 and another end connected to an electric heating tube 200. Except for
the above, the electrical connector 400 has the same structure as the electrical connector
100 shown in Figure 1, which will not be described herein.
[0039] Figures 11 to 14 show a fluid state test device according to the present application.
The fluid state test device according to the present application may be configured
to process a pressure signal and a temperature signal and the like acquired by the
electrical connector 100, and further the state of the fluid is obtained. For the
purpose of clear illustration, Figures 11 to 14 respectively show processors, configured
to process the pressure signal and the temperature signal acquired by the electrical
connector 100, and so on.
[0040] As shown in Figure 11, the fluid state test device includes the electrical connector
100 and a first pressure measurement portion 180. The first pressure measurement portion
180 is connected to the total pressure output port 143 and the static pressure output
port 153 of the electrical connector 100, for measuring pressure values acquired from
the total pressure output port 143 and the static pressure output port 153. In this
embodiment, the first pressure measurement portion 180 is a diaphragm differential
pressure sensor, and the diaphragm differential pressure sensor includes two cavities
separated by a diaphragm, and the two cavities are respectively in communication with
the total pressure output port 143 and the static pressure output port 153 through
the pressure transmission channels. The diaphragm differential pressure sensor may
output a differential pressure, that is, the dynamic pressure, between the total pressure
and the static pressure. Alternatively, the first pressure measurement portion 180
may include two pressure sensors, that is, a first pressure sensor and a second pressure
sensor, respectively. The first pressure sensor is connected to the total pressure
output port 143 and the second pressure sensor is connected to the static pressure
output port 153, for measuring the total pressure and the static pressure of the fluid
respectively. Furthermore, the fluid state test device further includes a flow speed
calculation unit (not shown in the figure), and the flow speed calculation unit may
calculate the flow speed of the fluid flowing through the electrical connector 100
based on the differential pressure output by the differential pressure sensor or based
on the dynamic pressure and the static pressure. Furthermore, the fluid state test
device may further calculate the flow rate of the fluid flowing through the electrical
connector 100 based on the flow speed. Such measurements of the state of the fluid
contribute to acquiring information about the longitudinal vibration of the electrical
connector 100, and further the state of the fluid may be adjusted or the structure
of the electrical connector 100 may be designed, thus the longitudinal vibration of
the electrical connector 100 is adjusted and improved.
[0041] As shown in Figure 12, in addition to the first pressure measurement portion 180,
the fluid state test device may further include a second pressure measurement portion
230. The second pressure measurement portion 230 is connected to the total pressure
output port 143 and the back pressure output port 213 of the electrical connector
100, for measuring the value of a differential pressure between the total pressure
output port 143 and the back pressure output port 213. A pressure measurement structure
of the second pressure measurement portion 230 is the same as the structure of the
first pressure measurement portion 180 through which the pressure of each of the total
pressure acquisition portion 140 and the static pressure acquisition portion 150 is
measured . In Figure 12, the second pressure measurement portion 230 is a diaphragm
differential pressure sensor, and the diaphragm differential pressure sensor includes
two cavities separated by a diaphragm, and the two cavities are respectively in communication
with the total pressure output port 143 and the back pressure output port 213 through
the pressure transmission channels. The diaphragm differential pressure sensor may
output a differential pressure between the total pressure and the back pressure. Alternatively,
the second pressure measurement portion 230 may include two pressure sensors, that
is, a first pressure sensor and a second pressure sensor. The first pressure sensor
is connected to the total pressure output port 143 and the second pressure sensor
is connected to the back pressure output port 213, for measuring the total pressure
and the back pressure of the fluid respectively. Furthermore, the fluid state test
device further includes a resistance coefficient calculation unit 240. The dynamic
pressure is calculated by a multiplier 241 of the resistance coefficient calculation
unit 240, based on a product of a dynamic pressure (the difference between the total
pressure and the static pressure) obtained by the first pressure measurement portion
180 and the projection area of the upstream side. Then, the resistance of the electrical
connector 100 is calculated by a multiplier 242, based on a product of a differential
pressure (a difference between the total pressure and the back pressure) obtained
by the second pressure measurement portion 230 and the projection area of the upstream
side. Finally, the resistance coefficient C
d, that is, resistance/dynamic pressure, of the electrical connector 100 in the flow
channel of the fluid is calculated by a divider 243, further, a specific thickness
dimension and a specific width dimension of the electrical connector 100 are obtained,
thus, optimal design of a characteristic scale of the electrical connector 100 is
achieved.
[0042] As shown in Figure 13, the fluid state test device may further include a frequency
calculation unit 190. The frequency calculation unit 190 is connected to the first
temperature sensing element 181 and the second temperature sensing element 182, for
measuring the lateral vibration frequency of the electrical connector. The frequency
calculation unit 190 is configured to receive a signal indicative of the temperature
from each of the first temperature sensing element 181 and the second temperature
sensing element 182 and calculate the frequency of the alternating force applied by
the fluid on the electrical connector 100 in the direction perpendicular to the flow
direction of the fluid, that is, the lateral vibration frequency of the electrical
connector 100. The signal, indicative of the temperature, from each of the first temperature
sensing element 181 and the second temperature sensing element 182 is led to the frequency
calculation unit 190 by a respective sensor lead (not shown in the figure). In order
to prevent the sensor lead from impeding the fluid flowing through each of the first
side 112 and the second side 113 without affecting the measurement accuracy, the sensor
lead of each of the two temperature sensing elements may be configured to pass through
a lead channel preformed in the electrical connector 100. Alternatively, the sensor
lead is arranged in a slot formed in the surface of the main body portion 110, and
the sensor lead does not go beyond the surface of the first side 112 and the surface
of the second side 113, preferably, a peripheral top portion of the sensor lead is
flush with the surface of the first side 112 and the surface of the second side 113.
In this way, the fluid boundary layer at a side of the electrical connector may not
be affected. The sensor lead may be led out from the connection surface (or surfaces)
or the end (or ends) of one or two of the first connection portion 120 and the second
connection portion 130. Preferably, the sensor lead of the first temperature sensing
element 181 and the sensor lead of the second temperature sensing element 182 may
be led out from the same connection portion, that is, the first connection portion
120 or the second connection portion 130. Preferably, the frequency calculation unit
190 is provided outside the flow channel, and the sensor lead is configured to pass
through a wall of the flow channel to be connected to the frequency calculation unit
190, thus providing the signal indicative of the temperature to the frequency calculation
unit 190. Similarly, the first pressure measurement portion 180 and the second pressure
measurement portion 230 and other signal processors may also be provided outside the
wall of the flow channel, and may be connected to the total pressure acquisition portion
140, the static pressure acquisition portion 150 and the back pressure acquisition
portion 210 by corresponding leads.
[0043] Figure 14 further shows the configuration of a circuit of the frequency calculation
unit 190 according to an embodiment of the present application. The frequency calculation
unit 190 includes a first bridge resistor 191, a second bridge resistor 192, a constant
current source 193, a power supply 194, an amplifier 195, a filter 196, a flip-flop
197 and a converter 198. The first temperature sensing element 181, the first bridge
resistor 191, the second bridge resistor 192 and the second temperature sensing element
182 are electrically connected in order into a bridge circuit. A node between the
first temperature sensing element 181 and the second temperature sensing element 182
and a node between the first bridge resistor 191 and the second bridge resistor 192
are respectively connected to two electrodes of the constant current source 193. The
constant current source 193 is connected to the power supply 194, for maintaining
a current provided by the power supply 194 to the bridge circuit through the constant
current source 193 constant. A node between the first temperature sensing element
181 and the first bridge resistor 191 and a node between the second temperature sensing
element 182 and the second bridge resistor 192 are connected to the amplifier 195
by wires, for outputting a voltage signal to the amplifier 195. The first temperature
sensing element 181 has the same structure as the second temperature sensing element
182. The first bridge resistor 191 and the second bridge resistor 192 may have the
same resistance value, and a balanced electric bridge is adopted to measure, so that
the voltage signal initially output is zero. Alternatively, the first bridge resistor
191 and the second bridge resistor 192 may have different resistance values, and an
imbalanced electric bridge is adopted to measure, that is, the voltage signal initially
output is not equal to zero. The first temperature sensing element 181 and the second
temperature sensing element 182 are energized with constant current. In the case that
Karman vortex street does not occur on each of the first side 112 and the second side
113 of the electrical connector 100 and the lateral vibration, in the direction perpendicular
to the flow direction of the fluid, of the electrical connector 100 is not induced,
the first temperature sensing element 181 has the same temperature as the second temperature
sensing element 182, so that resistance values to which the first temperature sensing
element 181 and the second temperature sensing element 182 correspond in the bridge
circuit are equal and an input voltage of the amplifier 195 is zero. In the case that
the Karman vortex street occurs on each of the first side 112 and the second side
113 of the electrical connector 100 and the lateral vibration, in the direction perpendicular
to the flow direction of the fluid, of the electrical connector 100 is induced, the
temperatures sensed by the first temperature sensing element 181 and the second temperature
sensing element 182, on the first side 112 and the second side 113 are inconsistent
due to downstream shedding of the vortex, such a difference in temperature causes
the bridge circuit to output voltage to the amplifier 195. The voltage, after being
processed by the filter 196 and the flip-flop 197, is output as a pulse signal indicative
of the frequency of the alternating force acting on the side of the electrical connector
100, and an output frequency of the pulse signal represents the lateral vibration
frequency of the electrical connector 100. The flip-flop 197 may further be connected
to the converter 198, and thus the pulse signal is processed by the converter 198
to be output as an analogue signal. The analogue signal represents variation of the
intensity of convective heat exchange of the fluid on the first side 112 and the second
side 113. Preferably, the first temperature sensing element 181 and the second temperature
sensing element 182 should both adopt an element with a small time constant, thus
facilitates sensing of the frequency of the shedding of the vortex. Preferably, the
temperature sensing element may be a thermistor which is sensitive to the temperature
and may exhibit different resistance values at different temperatures. Alternatively,
the temperature sensing element may also be a thermal resistor, a thermocouple, a
fiber optic temperature sensor and the like. In other embodiments, the frequency calculation
unit 190 may be embodied as any devices capable of measuring frequency, such as an
oscilloscope.
[0044] Figures 15 to 18 show a fluid heat exchange system provided with the electrical connector
100. The charged element is an electric heating element capable of generating heat,
and in this embodiment, the charged element is the electric heating tube 200. As shown
in Figure 15, the fluid heat exchange system includes a circular ring shaped flow
channel 300, multiple electric heating tubes 200 arranged in the fluid flow channel
and multiple electrical connectors 100 configured to electrically connect the multiple
electric heating tubes 200. The fluid flowing in the fluid flow channel 300 may be
liquid or gas.
[0045] Figure 16 shows the structure of the electric heating tube 200. The electric heating
tube 200 includes a metal outer tube 201, a resistance wire 202 arranged in the metal
outer tube 201, and a filler 203 filled in the metal outer tube 201. Crystalline magnesium
oxide powder with a good insulativity and a good thermal conductivity is typically
selected as the filler. In order to improve a heat dissipation effect of the metal
outer tube 201, an outer periphery of the metal outer tube 201 is surrounded by a
helical fin 206. The electric heating tube 200 is W-shaped. An outer periphery of
each of two ends of the metal outer tube 201 is provided with threads, and each of
the two ends passes through a connection hole in a fixed end 301 provided in an inner
wall of the flow channel and is secured to the fixed end 301by a nut, so that the
electric heating tube 201 is fixed, in the direction parallel to the flow direction
of the fluid, to the inner wall of the flow channel. Two electrodes 204 are respectively
provided at the two ends of the metal outer tube 201. An outer periphery of the electrode
204 is provided with threads, to allow the electrode 204 to be connected to the electrical
connector 100.
[0046] Figure 15 shows a connection manner between the electrical connector 100 and the
electrode 204 of the electric heating tube 200. The electrode 204 passes through the
connection hole 121 provided in the first connection portion 120 or the connection
hole 131 provided in the second connection portion 130 of the electrical connector
100, and the electrode 204 is secured to the electrical connector 100 by a nut. An
insulation ceramic head 205 is further provided between the electrode 204 of the electric
heating tube 200 and the end of the metal outer tube 201, for achieving electrical
insulation between the electrical connector 100 and the metal outer tube 201.
[0047] Figure 17 shows a plane outspread structure of the electric heating tube 200 and
the electrical connector 100 arranged in the flow channel 300. In the figure, g indicates
a downward gravity, which is consistent with the flow direction of the fluid longitudinally
passing through the electric heating tube 200, and the electrodes of the electric
heat source and the electrical connector thereof are located upstream of the helical
fin of the electric heating tube. As shown in the figure, by taking six electric heating
tubes 200 as an example, the six electric heating tubes 200 are evenly distributed
in the fluid flow channel 300 in a circumferential direction. In the fluid heat exchange
system, the six electric heating tubes 200 as electric energy loads may be supplied
with split-phase power supply, for example, the split phases are phase A (i.e. phase
U), phase B (i.e. phase V) and phase C (i.e. phase W). As shown in the figure, two
electric heating tubes 200 are electrically connected between the phase A and neutral
wires N, and the two electric heating tubes 200 are respectively connected between
a power supply phase wire A1 and a neutral wire N and between a power supply phase
wire A2 and a neutral wire N. Two electric heating tubes 200 are electrically connected
between the phase B and the neutral wires N, and the two electric heating tubes 200
are respectively connected between a power supply phase wire B1 and a neutral wire
N and between a power supply phase wire B2 and a neutral wire N. Two electric heating
tubes 200 are electrically connected among the phase C and the neutral wires N, and
the two electric heating tubes 200 are respectively introduced between a power supply
phase wire C1 and a neutral wire N and between a power supply phase wire C2 and a
neutral wire N. Alternatively, other number of electric heating tubes may be electrically
connected between the phase A, the phase B, the phase C and the neutral wires N. Further,
in addition to a three-phase power supply manner, other split-phase power supply manners
may be used. The electrodes of the electric heating tube 200 are arranged upward,
so that the electrical connector 100 is located upstream with respect to the electric
heating tube 200 in the flow direction of the fluid. Alternatively, as shown in Figure
18, the electrodes of the electric heating tube 200 are all arranged downward, so
that the electrical connector 100 is located downstream with respect to the electric
heating tube 200 in the flow direction of the fluid. The width of the electrical connector
is greater than the thickness of the electrical connector, and the electrical connector
is located at a lee side downstream of the helical fin of the electric heating tube.
By taking a U-phase load in Figure 17 as an example, two electric heating tubes are
connected in parallel to each other, that is, phase wires of the two electric heating
tubes are connected by the electrical connector 100 and the neutral wires of the two
electric heating tubes are connected by the electrical connector 100. The two adjacent
electrical connectors 100 are spaced apart from each other. Alternatively, the electrical
connectors 100 in the same phase load may further be connected in series or connected
in parallel-series by the electrical connector 100.
[0048] By using the electrical connector 100 and the fluid state test device according to
the present application, the flow state of the fluid may be acquired, measured and
monitored, and accordingly the state of the fluid may be adjusted. In one aspect,
by the total pressure acquisition portion 140 and the static pressure acquisition
portion 150 provided on the electrical connector 100, the pressure of the fluid flowing
through a certain measurement position of the electrical connector 100 may be collected;
and the flow speed of the fluid at the measurement position may be acquired based
on the dynamic pressure applied by the fluid on the electrical connector 100, that
is, the difference between the total pressure and the static pressure. In the fluid
heat exchange system, the flow speed of the fluid is an important factor affecting
the heat exchange efficiency between the electrical connector 100 and the fluid. If
the flow speed is too fast, in one aspect, impact on the electrical connector 100
may be caused and vibration in the flow direction of the fluid is caused, resulting
in fatigue failure of the electrode of the electric heating tube, and in another aspect,
the pressure loss may be increased, thus may both weaken the heat exchange effect
directly. In another aspect, by the back pressure acquisition portion 210 provided
on the electrical connector 100, the resistance coefficient of the electrical connector
100 to the fluid may be obtained, and based on the resistance coefficient, the feature
size of the electrical connector having a rectangular cross-section is optimally designed,
thus the effects of reducing the resistance and weakening the longitudinal vibration
are achieved.
[0049] The electrical connector 100 and the fluid state test device according to the present
application may be configured to measure and monitor the flow speed of the fluid,
so as control the flow speed of the fluid within a range which facilitates the heat
exchange efficiency and ensures the electrode not to be damaged. For example, the
lateral vibration of the electrical connector 100 is a main reason for the fatigue
failure of the electrode of the electric heating tube connected to the electrical
connector 100. By the temperature sensing elements provided on the two sides of the
electrical connector 100, the electrical connector 100 in this embodiment of the present
application may be configured to measure the lateral vibration frequency of the electrical
connector 100, thus the lateral vibration frequency of the electrical connector 100
may be adjusted by controlling the flow state of the fluid to control the lateral
vibration frequency within a range which may not adversely affect the electrode of
the electric heating tube. Also, since such acquisition of the vibration frequency
may provide a valuable fatigue test basis for an insulated fixation manner of the
insulation ceramic head and an insulated fixation manner of fixing the led-out electrode
to a casing, a test method may be performed using the electrical connector 100 according
to the embodiment of the present application. By simulating a real environment in
which the electric heating tube is located and by changing a transmission speed of
the fluid with a speed regulator, the frequency of a lateral vibration perpendicular
to the flow direction of the fluid, causing by the Karman vortex street occurring
at different flow speeds, of the electrical connector with a different width and a
different thickness or another non-circular structure at a certain scale is obtained,
and further the law of fluid flow-induced vibration is obtained. Based on the test
method, the flow state of the fluid, the structure of the electrical connector and
the like are pre-designed, to avoid a destruction effect of high-frequency vibration
of the electrical connector on the flow field.
[0050] Although the present application is described with reference to exemplary embodiments,
it should be understood that the present application is not limited to configurations
and methods of the embodiments described above. On the contrary, the present application
is intended to cover various modifications and equivalent configurations. In addition,
although various elements and method steps of the present application disclosed are
shown in various exemplary combinations and configurations, other combinations including
more or less elements or methods are also deemed to fall within the scope of the present
application.
1. An electrical connector (100,400) configured to measure a state of a fluid in a flow
channel, comprising:
a main body portion (110,410),
connection portions (120,130,420,430),
a total pressure acquisition portion (140), and
a static pressure acquisition portion (150), wherein
the connection portions (120,130,420,430) allow the main body portion (110,410) to
be electrically connected to a charged element provided in the flow channel;
the total pressure acquisition portion (140) comprises a total pressure measuring
hole (141) provided in a first part, facing a flow direction of the fluid, of the
main body portion (110,410); and
the static pressure acquisition portion (150) comprises a static pressure measuring
hole (151) provided in a second part, parallel to the flow direction of the fluid,
of the main body portion (110,410).
2. The electrical connector (100,400) according to claim 1, wherein the main body portion
(110,410) comprises an upstream side (111), a first side (112) and a second side (113),
the upstream side (111) faces the flow direction of the fluid, the first side (112)
and the second side (113) are parallel to the flow direction of the fluid, and the
first part is located on the upstream side (111), and the second part is located on
at least one of the first side (112) and the second side (113).
3. The electrical connector (100,400) according to claim 2, wherein the upstream side
(111) is a flat surface or a curved surface.
4. The electrical connector (100,400) according to claim 3, wherein a surface where the
first part is located is perpendicular to the flow direction of the fluid.
5. The electrical connector (100,400) according to claim 2, wherein the first side (112)
and the second side (113) are parallel to each other, and both the first side (112)
and the second side (113) are flat surfaces or curved surfaces.
6. The electrical connector (100,400) according to claim 1, wherein a size of the main
body portion (110,410) in a direction parallel to the flow direction of the fluid
is greater than a size of the main body portion (110,410) in a direction perpendicular
to the flow direction of the fluid.
7. The electrical connector (100,400) according to claim 6, wherein a cross-section of
the main body portion (110,410) in the direction perpendicular to the flow direction
of the fluid is rectangular, and a ratio of width to thickness of the main body portion
(110,410) is greater than 4.
8. The electrical connector (100,400) according to claim 1, wherein a size of each of
the connection portions (120,130,420,430) in a direction perpendicular to the flow
direction of the fluid is greater than a size of the main body portion (110,410) in
a direction perpendicular to the flow direction of the fluid.
9. The electrical connector (100,400) according to claim 8, wherein the connection portions
(120,130,420,430) are located at ends of the main body portion (110,410), and a twist
portion (160,170) is provided between each of the connection portions (120,130,420,430)
and the main body portion (110,410) to allow the connection portion (120,130,420,430)
to twist by a certain angle with respect to the main body portion (110,410).
10. The electrical connector (100,400) according to claim 9, wherein each of the connection
portions (120,130,420,430) is twisted by 90 degrees with respect to the main body
portion (110,410).
11. The electrical connector (100,400) according to claim 1, wherein an axial direction
of the total pressure measuring hole (141) is parallel to the flow direction of the
fluid.
12. The electrical connector (100,400) according to claim 11, wherein the axial direction
of the total pressure measuring hole (141) perpendicularly intersects an axial direction
of the static pressure measuring hole (151).
13. The electrical connector (100,400) according to claim 2, wherein the total pressure
measuring hole (141) is provided at a central position of the upstream side (111).
14. The electrical connector (100,400) according to claim 1, wherein the total pressure
acquisition portion (140) further comprises a total pressure output port (143) and
a total pressure transmission channel (142), the total pressure output port (143)
is provided in one of the main body portion (110,410) and the connection portions
(120,130,420,430), and the total pressure transmission channel (142) is provided in
the main body portion (110,410) and/or the connection portions (120,130,420,430) to
allow the total pressure measuring hole (141) to be in communication with the total
pressure output port (143).
15. The electrical connector (100,400) according to claim 14, wherein the total pressure
output port (143) is provided in a surface of the connection portion (120,130,420,430).
16. The electrical connector (100,400) according to claim 14, wherein the static pressure
acquisition portion (150) further comprises a static pressure output port (153) and
a static pressure transmission channel (152), the static pressure output port (153)
is provided in one of the main body portion (110,410) and the connection portion (120,130,420,430),
and the static pressure transmission channel (152) is provided in the main body portion
(110,410) and/or the connection portion (120,130,420,430) to allow the static pressure
measuring hole (151) to be in communication with the static pressure output port (153).
17. The electrical connector (100,400) according to claim 16, wherein the static pressure
output port (153) is provided in a surface of the connection portion (120,130,420,430).
18. The electrical connector (100,400) according to claim 16, further comprising a back
pressure acquisition portion (210), wherein the back pressure acquisition portion
(210) comprises a back pressure measuring hole (211) provided in a third part, away
from the flow direction of the fluid, of main body portion (110,410).
19. The electrical connector (100,400) according to claim 18, wherein the main body portion
(110,410) comprises a downstream side (116) away from the flow direction of the fluid,
and the third part is located on the downstream side (116).
20. The electrical connector (100,400) according to claim 18, wherein the back pressure
acquisition portion (210) further comprises a back pressure output port (213) and
a back pressure transmission channel (212), the back pressure output port (213) is
provided in one of the main body portion (110,410) and the connection portion (120,130,420,430),
and the back pressure transmission channel (152) is provided in the main body portion
(110,410) and/or the connection portion (120,130,420,430) to allow the back pressure
measuring hole (211) to be in communication with the back pressure output port (213).
21. The electrical connector (100,400) according to claim 2, further comprising:
a first temperature sensing element (181), and
a second temperature sensing element (182), wherein
the first temperature sensing element (181) and the second temperature sensing element
(182) are respectively provided at mutually opposite positions on the first side (112)
and the second side (113) in an electrically insulated manner.
22. The electrical connector (100,400) according to claim 21, wherein an outer surface
of the first temperature sensing element (181) is flush with the first side (112),
an outer surface of the second temperature sensing element (182) is flush with the
second side (113), the outer surface of the first temperature sensing element (181)
has the same surface structure as the first side (112), and the outer surface of the
second temperature sensing element (182) has the same surface structure as the second
side (113).
23. The electrical connector (100,400) according to claim 21, wherein a first temperature
sensing element mounting recess (114) and a second temperature sensing element mounting
recess (115) are respectively provided in the first side (112) and the second side
(113).
24. The electrical connector (100,400) according to claim 23, wherein an electrically
insulation layer is provided on each of a surface of the first temperature sensing
element mounting recess (114) and a surface of the second temperature sensing element
mounting recess (115).
25. The electrical connector (100,400) according to claim 1, wherein a helical protrusion
is provided on an outer surface of the main body portion (110,410).
26. The electrical connector (100,400) according to claim 18, wherein a helical protrusion
is provided on an outer surface of the main body portion (110,410).
27. The electrical connector (100,400) according to claim 25 or 26, wherein the helical
protrusion is a helical wire (220) wound around the outer surface of the main body
portion (110,410).
28. The electrical connector (100,400) according to claim 25 or 26, wherein the helical
protrusion is integrally formed by a coating coated on the outer surface of the main
body portion (110,410).
29. The electrical connector (100,400) according to claim 26, wherein the helical protrusion
is away from a region where at least one of the total pressure measuring hole (141),
the static pressure measuring hole (151) and the back pressure measuring hole (211)
is located.
30. A fluid state test device, comprising:
an electrical connector (100,400) comprising:
a main body portion (110,410);
connection portions (120,130,420,430) allowing the main body portion (110,410) to
be electrically connected to a charged element provided in a flow channel;
a total pressure acquisition portion (140), wherein the total pressure acquisition
portion (140) comprises a total pressure measuring hole (141), and the total pressure
measuring hole (141) is provided in a first part, facing a flow direction of fluid,
of the main body portion (110,410); and
a static pressure acquisition portion (150), wherein the static pressure acquisition
portion (150) comprises a static pressure measuring hole (151), and the static pressure
measuring hole (151) is provided in a second part, parallel to the flow direction
of the fluid, of the main body portion (110,410); and
a first pressure measurement portion (180) connected to the total pressure measuring
hole (141) and the static pressure measuring hole (151) respectively for measuring
a pressure state of the fluid.
31. The fluid state test device according to claim 30, wherein the main body portion (110,410)
comprises an upstream side (111), a first side (112) and a second side (113), the
upstream side (111) faces the flow direction of the fluid, the first side (112) and
the second side (113) are parallel to the flow direction of the fluid, the first part
is located on the upstream side (111), and the second part is located on at least
one of the first side (112) and the second side (113).
32. The fluid state test device according to claim 30, wherein a size of the main body
portion (110,410) in a direction parallel to the flow direction of the fluid is greater
than a size of the main body portion (110,410) in a direction perpendicular to the
flow direction of the fluid.
33. The fluid state test device according to claim 32, wherein a cross-section of the
main body portion (110,410) in the direction perpendicular to the flow direction of
the fluid is rectangular, and a ratio of width to thickness of the main body portion
(110,410) is greater than 4.
34. The fluid state test device according to claim 30, wherein the connection portion
(120,130,420,430) is located at an end of the main body portion (110,410), and a twist
portion (160,170) is provided between each of the connection portions (120,130,420,430)
and the main body portion (110,410) to allow the connection portion (120,130,420,430)
to twist by a certain angle with respect to the main body portion (110,410).
35. The fluid state test device according to claim 30, wherein an axial direction of the
total pressure measuring hole (141) is parallel to the flow direction of the fluid.
36. The fluid state test device according to claim 35, wherein the axial direction of
the total pressure measuring hole (141) perpendicularly intersects an axial direction
of the static pressure measuring hole (151).
37. The fluid state test device according to claim 30, wherein the total pressure acquisition
portion (140) further comprises a total pressure output port (143) and a total pressure
transmission channel (142), the total pressure output port (143) is provided in one
of the main body portion (110,410) and the connection portion (120,130,420,430), and
the total pressure transmission channel (142) is provided in the main body portion
(110,410) and/or the connection portion (120,130,420,430) to allow the total pressure
measuring hole (141) to be in communication with the total pressure output port (143).
38. The fluid state test device according to claim 30, wherein the static pressure acquisition
portion (150) further comprises a static pressure output port (153) and a static pressure
transmission channel (152), the static pressure output port (153) is provided in one
of the main body portion (110,410) and the connection portion (120,130,420,430), and
the static pressure transmission channel (152) is provided inside the main body portion
(110,410) and/or the connection portion (120,130,420,430) to allow the static pressure
measuring hole (151) to be in communication with the static pressure output port (153).
39. The fluid state test device according to claim 38, wherein the first pressure measurement
portion (180) comprises a first sensor and a second sensor, the first sensor is connected
to the total pressure output port (143), and the second sensor is connected to the
static pressure output port (153).
40. The fluid state test device according to claim 38, wherein the first pressure measurement
portion (180) comprises a pressure transmission channel and a differential pressure
sensor, and the differential pressure sensor is in communication with the total pressure
output port (143) and the static pressure output port (153) through the pressure transmission
channels respectively.
41. The fluid state test device according to claim 30, further comprising:
a flow speed calculation unit, wherein the flow speed calculation unit is configured
to calculate a flow speed of the fluid located upstream of the electrical connector
(100,400) based on a dynamic pressure of the fluid at the total pressure measuring
hole (141) obtained through the first pressure measurement portion (180).
42. The fluid state test device according to claim 30, wherein the electrical connector
(100,400) further comprises: a back pressure acquisition portion (210);
the back pressure acquisition portion (210) comprises a back pressure measuring hole
(211), and the back pressure measuring hole (211) is provided in a third part, away
from the flow direction of the fluid, of main body portion (110,410).
43. The fluid state test device according to claim 42, wherein the back pressure acquisition
portion (210) further comprises a back pressure output port (213) and a back pressure
transmission channel (212);
the back pressure output port (213) is provided in one of the main body portion (110,410)
and the connection portion (120,130,420,430), and the back pressure transmission channel
(152) is provided in the main body portion (110,410) and/or the connection portion
(120,130,420,430) to allow the back pressure measuring hole (211) to be in communication
with the back pressure output port (213).
44. The fluid state test device according to claim 42, further comprising a second pressure
measurement portion (230), wherein the second pressure measurement portion (230) is
connected to the total pressure measuring hole (141) and the back pressure measuring
hole (211) respectively to measure a pressure state of the fluid.
45. The fluid state test device according to claim 31, further comprising:
a first temperature sensing element (181), and
a second temperature sensing element (182), wherein
the first temperature sensing element (181) and the second temperature sensing element
(182) are respectively provided at mutually opposite positions on the first side (112)
and the second side (113) in an electrically insulated manner.
46. The fluid state test device according to claim 45, further comprising:
a frequency calculation unit (190) which is configured to calculate a frequency of
an alternating force applied by the fluid on the electrical connector (100,400) in
a direction perpendicular to the flow direction of the fluid, based on an alternating
change of a measurement value of each of the first temperature sensing element (181)
and the second temperature sensing element (182).
47. The fluid state test device according to claim 46, wherein the frequency calculation
unit (190) is an oscilloscope.
48. The fluid state test device according to claim 46, wherein the frequency calculation
unit (190) comprises a first bridge resistor (191), a second bridge resistor (192),
a direct-current power source and a calculation circuit;
the first temperature sensing element (181), the first bridge resistor (191), the
second bridge resistor (192) and the second temperature sensing element (182) are
electrically connected in order to form a return circuit;
a node between the first temperature sensing element (181) and the second temperature
sensing element (182) and a node between the first bridge resistor (191) and the second
bridge resistor (192) are respectively connected to two electrodes of the direct-current
power source; and
the calculation circuit is configured to calculate the frequency of the alternating
force based on an alternating change of an output voltage between a node between the
first temperature sensing element (181) and the first bridge resistor (191) and a
node between the second temperature sensing element (182) and the second bridge resistor
(192).
49. The fluid state test device according to claim 48, wherein the calculation circuit
comprises an amplifier (195), a filter (196) and a flip-flop (197);
the amplifier (195), the filter (196) and the flip-flop (197) are connected in order,
the output voltage is output to the amplifier (195), the flip-flop (197) is configured
to output a pulse signal indicative of the frequency of the alternating force, and
the calculation circuit further comprises a converter (198) connected to an output
end of the flip-flop (197) to allow the converter (198) to output an analogue signal
indicative of the frequency of the alternating force.
50. A fluid heat exchange system, comprising:
a flow channel (300) through which fluid flows;
a charged element fixed to the flow channel, wherein the charged element is an electric
heating element, and the electric heating element comprises a heating body and an
electrode (204) located at an end of the heating body; and
the fluid state test device according to any one of claims 32 to 52, wherein the electrical
connector (100,400) is connected to the electrode (204) of the electric heating element.
51. The fluid heat exchange system according to claim 50, wherein the electric heating
element is an electric heating tube (200).